World-wide, plant-parasitic nematodes are among the most devastating pathogens of life sustaining crops. In 1984, nematodes accounted for more than fifty billion dollar s (US) in economic losses. The United States' portion of this figure alone is almost six billion dollars. Genetic resistance to certain nematode species is available in some cultivars, but these are restricted in number, and the availability of cultivars with both desirable agronomic features and resistance is limited. In addition, traditional methods for plant breeding require 5-10 years to produce a viable cultivar, while the need for new nematode control tools is immediate and critical.
The major means of nematode control has been the application of chemical nematicides. During 1982, in the United States alone over 100 million pounds of nematicide were applied to crops. Chemical nematicides are generally highly toxic compounds known to cause substantial environmental impact. In the past several years, issues such as ground water contamination, mammalian and avian toxicity, and residues in food have caused much tighter restrictions on the use of chemical nematicides. Unfortunately, in many situations there is no alternative available for growers who rely upon nematicides to protect their crop from root-knot and cyst nematodes. Accordingly, there is a continuing need for new ways to combat nematodes in plants.